Regulation of KDM5C stability and enhancer reprogramming in breast cancer.

Abnormality of enhancer regulation has emerged as one of the critical features for cancer cells. KDM5C is a histone H3K4 demethylase and frequently mutated in several types of cancer. It is critical for H3K4me3 and activity of enhancers, but its regulatory mechanisms remain elusive. Here, we identify TRIM11 as one ubiquitin E3 ligase for KDM5C. TRIM11 interacts with KDM5C, catalyzes K48-linked ubiquitin chain on KDM5C, and promotes KDM5C degradation through proteasome. TRIM11 deficiency in an animal model represses the growth of breast tumor and stabilizes KDM5C. In breast cancer patient tissues, TRIM11 is highly expressed and KDM5C is lower expressed, and their expression is negatively correlated. Mechanistically, TRIM11 regulates the enhancer activity of genes involved in cell migration and immune response by targeting KDM5C. TRIM11 and KDM5C regulate MCAM expression and cell migration through targeting H3K4me3 on MCAM enhancer. Taken together, our study reveals novel mechanisms for enhancer regulation during breast cancer tumorigenesis and development.